Numerous devices have already been proposed for stabilising the frequency of a sprung balance regulating system. GB Patent No. 1 138 818, published in 1967, discloses a coupling device wherein the vibrations of a first oscillator excite a tuning fork via shocks, i.e. without any direct mechanical link. More recent regulating devices rely essentially on devices associating a mechanical regulator, such as a sprung balance, associated by electromagnetic coupling with an electronic regulator, said coupling being essentially achieved by means of magnets arranged in the arms or in the felloe of the balance. This type of device has been disclosed, for example, in U.S. Pat. No. 3,937,001. Numerous improvements have been made to this basic device; essentially concerning the design or arrangement of the magnets, the electronic circuit and the second resonator, and the energy source necessary for powering said electronic circuit. Such improvements are for example disclosed in EP Patent Nos. 0 679 968, 0 732 243, 0 806 710, 0 822 470, 0 848 306, 0 935 177 and 1 521 141.
All of these coupling devices have the drawback of being either unreliable, or requiring the assembly of a large number of components whose peculiar functions have to be adjusted in relation to each other, which eventually contributes to greatly increasing the cost of the final product.